CCNB3 and Infertility: The sds cycb3;1 mutations also slightly lessened the severity of tdm1 phenotypes: while they did not rescue infertility caused by TDM1 deficiency, not all meiocytes in sds cycb3;1 tdm1 triple mutants aborted and some formed large pollen-like cells apparent after Alexander staining (Figure 5D).These data indicate that SDS and CYCB3;1 at least partially contribute to the CDK activity that hinders meiotic exit in smg7 and tdm1 mutants.